Silver Mettle

As the NBA season this year is coming to a close, analysts are already looking forward to next season and some potential changes. One of the key changes being considered by NBA Commissioner Adam Silver is whether or not the league should extend the minimum age limit to play in the NBA from 19 to 20. Another is how, if at all, the NBA D-League should be restructured.
The solution to me seems obvious. The NBA should borrow the model in place with baseball and hockey. Major League Baseball has a developed minor league system, as does the NHL. Players can  be drafted into either professional sport directly out of high school. If they are good enough to play at the major league level, they play. If not, they play in the minor league system where they develop their skills, earn a living and, with luck, eventually ascend to the major league level.
The players, of course, can also choose to play college baseball or hockey (or Juniors Hockey, which is pretty much college hockey sans the schoolwork) and enter the draft at a later date. In the case of college baseball, players aren't eligible for draft until after their junior season. This helps baseball programs with their recruiting and development and, with recent examples of Evan Longoria, Buster Posey and Max Scherzer, doesn't seem to hurt player development or draft interest--in fact, recent high-rounder Gerrit Cole was drafted in the first round as both a high schooler and college player, so...
At any rate, the NBA could rescind the age limit, expand the number of rounds in the draft, connect D-League teams more directly to NBA affiliates and allow high school players to enter the draft. The occasional Kobe or LeBron could play immediately, others with promise that want to earn a living for a year or two prior to ascending to the league could do so and the rest could commit to college for three or more seasons. This would allow coaches to develop their programs over time and we'd have far more situations with veteran-led teams, like George Mason some years back or Mercer this year, creating added excitement in March Madness.
Certainly the absence of Jabari Parker, Julius Randle or Andrew Wiggins would hurt their respective teams, but it's doubtful in any given year the loss of a half dozen players of this caliber would hurt college basketball as an institution.
In time, as has been the case with college baseball, many college basketball players would come to understand their future in professional basketball is unlikely and be more encouraged to stay a fourth or fifth year and graduate or pursue post-graduate degrees. Then we, as fans, could benefit far more over the course of time from their educations, than simply rooting for these players a few years while wearing Carolina blue.
And think of the benefit to the D-League. If the Kings, for instance, drafted Jabari Parker and felt he wasn't quite ready, think of the interest that would create for Reno's games, where he would play and develop. Seems like a win-win, plus an extra win, scenario. If Silver wants to leave his own stamp on the NBA and get out of the shadow cast by David Stern, this is a move that would certainly do it.